Posts filed under ‘water’

Arsenic and other minerals have been removed from river water using solar power by a team of Peruvian and Chilean researchers.

Researchers from Peru’s National Engineering University and Chile’s Tarapacá University have photochemically purified water from the river Locumba near Tacna, a Peruvian town by the border with Chile.

The decontaminated water is used for agricultural irrigation, though depending on the level of decontamination achieved it could be used for human consumption in future.

The technology’s ease of use means it could be used in the countries involved with the research as well as Bolivia; Andean countries where natural contamination is present in many waterways.

Juan Rodríguez, coordinator of the research in Peru, told SciDev.Net that the technology is able to reduce high levels of arsenic contamination of currently 500 parts per billion (ppb) to about 30 ppb.

The researchers designed prototypes of electrochemical equipment and decontamination filters for use in rural or difficult to access areas, which for the moment can treat 20 cubic metres of water daily.

“Modular systems can process much higher volumes, so that’s what we’re trying to achieve,” Rodríguez said.

They used a photochemical system with tubes of glass or plastic to decontaminate the water. Based on reflections the tubes get solar radiation for a few hours, which can purify water contaminated with arsenic and make it suitable for consumption.

This system can also decontaminate boron and iron from water, as sunlight accelerates the rate at which minerals coagulate and can then be removed.

According to Rodríguez, this research is of importance for Bolivia, Chile and Peru because “the problem of arsenic in waterways is of natural origin and doesn’t distinguish between borders”.

This is my translation of a story written by Zoraida Portillo on the Science and Development Network, “Reducen contaminación por arsénico usando energía solar”, published on August 3, 2010.You can read the original in Spanish here.

SciDev.Net stories are published under a Creative Commons attribution license; my translation is available under the same license. Note this license is only for this page. Other works on this website are subject to other licenses; please contact me for details if you’d like to republish other parts of this site.

In many ways, ‘sustainability’ is the buzz word for a new millennium. As finite resources run low, levels of production and consumption increase. And while trends show that we are making the effort to live greener lives, the problem of pollution has not gone away, with the UK dumping more household waste into landfill than any other EU country. This books defines sustainability, outlines sustainability challenges and explores some possible solutions.

The information in this book comes from a wide range of sources and includes government reports and statistics, newspaper reports, features, magazine articles and surveys, literature from lobby groups and charitable organisations.

Australians travelling overseas should make the most of their time and offset their carbon emissions, according to Professor Tim Flannery, renowned scientist, author and 2007 Australian of the Year.

Professor Flannery spoke to a group of Australian expatriates about climate change at King’s College in London on World Environment Day last week.

“When I travel overseas I try to do as much as I can at once, and then get back to Australia and try to spend a lengthy time back home before I’ve got to come over again,” he said.

Professor Flannery talked about the impact of water deficits in Australia and how this is affecting major cities. However his main message was the importance of the UN climate summit in 2009, when a new international climate agreement could be made.

“If governments behave as selfishly, stupidly and secretly as they did at the last meeting, the climate change problem will continue,” he said.

Professor Flannery said it’s hard for Australians living overseas to get involved in debate back home, but there are still roles to play.

“One of the great things expats can do is act as a bridge between a country like the UK, which is doing so much, and Australia – so bring ideas back with you. I know it’s not easy to change the world, but there are lots of small things that can be done,” he said.

One small thing Professor Flannery wants people to do is change to more efficient light bulbs, rather than traditional incandescent ones. He said backpackers could do their bit to reduce carbon emissions by carrying compact fluorescent light bulbs and installing them as they travel. Australia has committed to banning incandescent light bulbs by 2010.

Professor Flannery’s visit to London coincided with the launch of his books, including his latest, ‘The Weather Makers’, in paperback in the UK.